According to the UNEP, since 1990 the world's primary forest area has shrunk by 300 million hectares, an area larger than Argentina.(Click to enlarge.)

The world’s rainforest ecosystem services—such as increased rainfall, soil stability, and a regulated climate—are integral to the successful production of food in many parts of the world. Rainforests in the Amazon and the Congo, for example, support rainfall in key, surrounding agricultural areas.

Here, we highlight just five of the many ecosystem services that rainforests provide to people and the planet:

Nutrient Cycling and Soil Formation

According to the Rainforest Conservation Fund, many of the world’s tropical rainforests live “on the edge,” meaning that they receive very few nutrient inputs from the outside and must produce most nutrients themselves. When left intact, a rainforest acts as a closed-loop system, recycling the nutrients it has created; without tree cover, however, these nutrients would be lost and the forest would not survive.

Soil formation is another important and related supporting service. Most rainforests are “wet deserts,” located in areas with acidic, clay-like soils that are low in nutrients and that normally cannot sustain much life. Trees and plants maintain soil quality by providing organic material, such as leaves and branches. Their roots anchor the soil and prevent it, as well as the nutrients within it, from being washed away by heavy rainfall. Rainforest soils are thus poorly adapted to agriculture, because once the vegetation is removed, the soil is highly vulnerable to erosion and nutrient leaching.

Rain Making

Some rainforest services extend across vast geographical areas. For example, the Amazon forest reportedly makes as much as 50 percent of its own rainfall, through a combination of processes. Paradise Earth, a global Paradise Earthrainforest conservation project, explains that the winds moving westward from the Atlantic Ocean carry moisture to the region, which the plants then recycle through transpiration, releasing it into the atmosphere through their leaves. This, and the region’s persistent cloud cover, add to humidity and form the basis of precipitation that moves throughout the region. When the moisture hits the high wall of the Andes, the water is deflected to the south, providing important rainfall that supports agriculture and hydropower production in south-central Brazil and northern Argentina. “The newly recognized Amazon rain machine is making a vital contribution to the Brazilian economy through its benefits to agro-industry and some hydro-electric facilities,” notes Paradise Earth.

Regulating Climate and Air Quality

Rainforests help to maintain balance by regulating numerous natural processes. According to Rainforest Concern, “Without rainforests continually recycling huge quantities of water, feeding the rivers, lakes and irrigation systems, droughts would become more common.”

Rainforests also help regulate air quality, while locking away carbon dioxide that would otherwise contribute to planetary warming. Unlike humans, trees absorb (breathe in) atmospheric carbon dioxide and produce (breathe out) oxygen. They use the extracted carbon as raw material for growth of their living parts, such as stems, leaves, and roots.

Provisioning Goods

Rainforests do not simply play supporting and regulating roles; they are also prolific producers of goods that provide economic value to people. According to the United Nations Environment Programme (UNEP), about 1.6 billion people worldwide rely on forests for their livelihoods. Rainforest trees, when extracted, provide human necessities such as wood, fiber, and fuel. In addition, rainforest species and processes provide an invaluable source of ideas for the growing field ofbiomimicry—the examination and emulation of nature to find solutions to human problems.

Beyond their extractive benefits, rainforests are vital for many local, often indigenous, communities that inhabit them. Among the goods and services they provide are fresh water, wild foods, wild fisheries, wood for fire and construction, fibers and other materials for arts and crafts, and natural biomedicines and pharmaceuticals.

Sustaining Culture

Rainforests are also crucial to culture and society. They are increasingly popular destinations for recreation and eco-tourism, and they hold considerable educational and scientific value. For those who live within or near them, they are a source of a deep sense of belonging, cultural heritage, and religious and spiritual significance. And, of course, their beauty provides immeasurable aesthetic value to the world at large.

According to UNEP, since 1990, the world’s primary forest area has decreased by 300 million hectares, an area larger than Argentina. Yet without the ecosystem services that forests provide, many natural and human processes would collapse. This scientific fact alone makes the natural treasures of Planet Earth worth saving.